Monster Mowdown

Your village are being invaded by monsters and every citizen has pack their things, but you refuse to give up and decided to stay and fight. You know that help will arrive soon.
This is a shooting game wherein the targets are the monsters. You need to defend the town. You earn money in each kill. You can use the money to buy better guns. Or you could use it to hire mercenaries, either way would help you in your campaign. The game would be harder as you make some progress, so choose better guns over mercenaries since that would help you a lot in the game.